Tests of inhibition of 35S-sulfate uptake into cells expressing Rv1739c by (A) 1 mM NEM, (B) 50 μM CCCP, (C) 5 mM Na sulfite, (D) 5 mM Na selenate, (E) 5 mM Na molybdate or Na thiosulfate, (F) 1 mM DIDS or 100 μM niflumate. 35S-sulfate concentration was 100 μM in the presence of sulfite, molybdate, or thiosulfate, and 50 μM in the presence of the other antagonists. Number of measurements is within parentheses.